Automotive exhaust system

ABSTRACT

The automotive exhaust system includes a plurality of exhaust pipes that feed into a common collector. The collector includes a venturi at the point where the exhaust gases enter the collector from the multiple exhaust pipes. The exhaust gases accelerate through the venturi by virtue that the venturi has a cross-sectional area smaller than that of the exhaust pipes and the collector. A plurality of vanes located in the venturi further accelerate the exhaust gases into a spinning vortex along the interior surface of the main body of the collector to efficiently and quickly expel the exhaust gases out from within the automotive exhaust system. The diameter of the venturi relative to the collector is specific to each diameter of tubing as matched with the corresponding vehicle specifications.

BACKGROUND OF THE INVENTION

The present invention relates to an automotive exhaust system. Moreparticularly, the invention relates to an automotive exhaust systemhaving an improved collector that accelerates the expulsion exhaustgases out the tailpipe.

Over the years, various exhaust systems have been designed to improvethe efficiency and power output of four-stroke internal combustion(“IC”) engines. Improvements in engine components and “super tuning,” asis more typically done in racing systems, have produced significantincreases in engine power, especially with respect to the exhaustsystem. The efficiency of expelling exhaust gases resultant from thecombustion process in an IC engine is important to the overallefficiency of the engine. For example, increasing exhaust systemefficiency can reduce fuel consumption of the IC engine whilemaintaining and improving output power.

The exhaust gases in an IC engine exit the piston cylinder chamberthrough an exhaust orifice and into an exhaust manifold. Typically, morethan one cylinder in multiple cylinder IC engines (e.g. four-cylinder,six-cylinder, eight-cylinder, etc.) share the same exhaust manifold.Here, exhaust gases travel through the exhaust orifice and flow into acommon pipe toward the catalytic converter, the muffler and eventuallyout through the tailpipe. The piston cylinders may be subject to backpressure because the exhaust gases from one cylinder build up in theexhaust manifold and can affect the next cylinder that opens to use theexhaust manifold.

For example, most automobiles have an IC engine that uses a four-strokecycle to produce the energy needed to operate the vehicle. The fourstrokes refer to intake, compression, combustion (power) and exhaustionof waste gases resultant from the compression process. Initially, amixture of fuel and air is forced into the piston cylinder during theintake stroke. The piston inside the cylinder compresses the fuel/airmixture during the compression stroke. Thereafter, the combustion stroketakes place by igniting the compressed fuel/air mixture with a sparkplug. The fuel burns and expands during this stroke to generate thepower necessary to move the piston. An exhaust valve opens at thebeginning of the exhaust stroke to allow the piston to push out theexhaust gases from within the cylinder. The intake, compression andexhaust strokes are all required to enable the power stroke. Thesestrokes all require energy and thereby reduce the amount of energy thatmay be used to operate the vehicle. This directly affects vehicleperformance, fuel consumption, efficiency and power.

The exhaust valve opens during the exhaust stroke to enable the exhaustgases produced during the combustion stroke to exit the cylinder throughthe exhaust orifice into the exhaust manifold. The exhaust gasespreferably efficiently exit the cylinder at high velocity. Any exhaustgases remaining in the exhaust system may have a tendency to stagnate oreven reverse direction due to a change in vacuum. This negative vacuumwhere exhaust gases are pulled back toward the piston cylinders, maysubsequently exert a resistive force on the next round of escapingexhaust gases when the exhaust valve of the next cylinder opens.Ultimately, this force may exert back pressure on the piston, therebypreventing efficient escape of the exhaust gases from within thecylinder. Additional power is wasted if the piston has to push againstthe back pressure to force the exhaust gases out. This action adverselycauses engine torque to fall below its optimum value and the enginesubsequently loses power and performance.

An exhaust header is a bolt-on engine accessory designed to improveengine performance by making it easier for the IC engine to push exhaustgases out from within the cylinders. Basically, the exhaust headerfunctions to eliminate back pressure in the exhaust manifold byconnecting multiple pipes to multiple exhaust valves in the IC engine,instead of relying on a single, common pipe. First, multiple exhaustpipes alone improve the flow of exhaust gases exiting the cylinder byefficiently providing a larger per-cylinder area through which theexhaust gases may exit. Second, each cylinder gets its own exhaust pipe,instead of sharing a common manifold. The multiple pipes come togetherinto a larger pipe called a collector. Ideally, each pipe is similarlycut and bent to the same length so that the exhaust gases from thevarious cylinders arrive in the collector spaced out equally toeliminate back pressure generated by the cylinder sharing the collector.Efficient removal of the exhaust gases from the point where the exhaustgases are collected in the collector further enhances the efficiency ofthe exhaust system such that the vehicle may maintain performance andpower. But, the prior art fails to disclose a system for efficiently andexpeditiously expelling exhaust gases through the collector and out theend of the tailpipe.

Thus, there exists a significant need for an improved automotive exhaustsystem capable of accelerating exhaust gases through a collector and outthrough the end of a tailpipe. Such an improved automotive exhaustsystem should include multiple exhaust pipes that feed into a commoncollector, should be capable of accelerating the exhaust gases at thepoint of entry into the collector from the multiple exhaust valves, andshould further be capable of creating a vortex of spinning escapingexhaust gas within the collector to quickly and efficiently expel theexhaust gas through the end of the tailpipe and into the atmosphere. Thepresent invention fulfills these needs and provides further relatedadvantages.

SUMMARY OF THE INVENTION

The improved automotive exhaust system of the present invention includesa plurality of exhaust pipes at the proximal end that join into a commoncollector at the distal end. The collector includes a venturi at thepoint of entry of the exhaust gases from the multiple exhaust pipes. Theventuri has a cross-sectional area smaller than that of thecross-sectional area of the pipes or the cross-sectional area of themain body of the connector. In turn, exhaust gases accelerate throughthe venturi and into the main body of the collector. Moreover, theventuri includes a plurality of vanes that further accelerate theexhaust gases into a spinning vortex along the interior surface of thecollector to quickly and efficiently expel the exhaust gases out the endof the tailpipe. The diameter of the venturi relative to the collectoris specific to each diameter of tubing as matched with the correspondingvehicle specifications.

Other features and advantages of the present invention will becomeapparent from the following more detailed description, when taken inconjunction with the accompanying drawings, which illustrate, by way ofexample, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate the invention. In such drawings:

FIG. 1 is a perspective view of an improved automotive exhaust system inaccordance with the present invention;

FIG. 2 is an end view of a collector integral to the automotive exhaustsystem;

FIG. 3 is an end view of a plurality of exhaust pipes feeding into thecollector; and

FIG. 4 is a schematic view illustrating the internal flow of exhaustgases through the exhaust pipes and the collector.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in the drawings for purposes of illustration, the presentinvention for an improved automotive exhaust system is referred togenerally by the reference number 10. The improved automotive exhaustsystem 10 generally includes a plurality of exhaust pipes 12 that feedinto a collector 14 through a venturi 16. FIG. 1 illustrates fourexhaust pipes 12 converging into a single collector 14. Otherembodiments may include any one of a number of plurality of exhaustpipes 12 that feed into a single collector 14, such as two, three, five,etc., in accordance with the present invention. In this respect, theexhaust pipes 12 are shown in FIG. 1 sectioned off from an exhaustheader for purposes of describing the improved automotive exhaust system10 of the present invention. A person of ordinary skill in the art willreadily recognize that the exhaust pipes 12 extend back into the exhaustheader that couples to the IC engine piston cylinders. That is, duringthe exhaust stroke in a four-stroke IC engine, exhaust gases exiting thepiston cylinder through the exhaust orifice enter the exhaust header andtravel through the exhaust pipes 12 into the collector 14. The exhaustpipes 12 may each correspond to a single, or less preferably, multipleexhaust orifices in an IC engine. For example, the automotive exhaustsystem 10 illustrated in FIG. 1 having four exhaust pipes 12 maycorrespond to a four-cylinder IC engine. Each of the exhaust pipes 12would be coupled to the exhaust orifice of each piston cylinder in theIC engine.

Exhaust gas traveling through the exhaust pipes 12 enter the venturi 16before entering the collector 14. As best shown in FIG. 1, the venturi16 is smaller in diameter than either the exhaust pipes 12 feedingtherein or the collector 14. To satisfy the equation of continuityaccording to Bernoulli's Principle, the velocity of the exhaust gasestraveling through the venturi 16 must increase as the area through whichthe exhaust gases travel is smaller relative to the exhaust pipes 12 andthe collector 14. The acceleration of exhaust gases through the venturi16 better expels the exhaust gases from the exhaust pipes 12, therebypreventing potential back pressure into the exhaust pipes 12, theexhaust header or the exhaust manifold. Similarly, the pressure of theexhaust gases traveling through the venturi 16 decreases due to theincrease in velocity. Of course, the velocity of the exhaust gases slowsdown in the collector 14 such that a simultaneous increase in pressureis observed due to the larger diameter of the collector 14 relative tothe venturi 16. The smaller diameter of the venturi 16 effectivelylimits any potential back pressure due to exhaust gases slowing down inthe collector 14, especially in view of the accelerated exhaust gasespassing through the venturi 16. That is, the automotive exhaust system10 of the present invention limits back flow, or reverse vacuum, becausethe venturi 16 is capable of accelerating the exhaust gases out of theexhaust pipes 12 and into the collector 14.

FIGS. 2 and 3 illustrate a set of exhaust vanes 18 disposed within theventuri 16, intermediate to the exhaust pipes 12 and the collector 14.Placement of the vanes 18 within the venturi 16 are also shown in theschematic view of FIG. 4. The vanes 18 located along the wall of theventuri 16 further accelerate and turn the exhaust gases traveling fromthe exhaust pipes 12 to the collector 14. That is, the vanes 18 create avortex of spinning exhaust gases along the outer edges of the wall ofthe venturi 16, which more quickly draws the exhaust gases through thecenter of the venturi 16. In turn, this further acceleration of theexhaust gases helps the performance of the automotive exhaust system 10.As best shown in FIGS. 3 and 4, the vanes 18 are arced to match theinterior wall of the venturi 16. The vanes 18 are also centereddownstream relative to each exhaust pipe 12 to best deflect and directthe exhaust in the correct direction. The vanes 18 may also be angledrelative to the adjacent wall within that arcuate section, depending onthe diameter of the venturi 16 and the size of the vanes 18. Thespinning exhaust then enters the collector 14, which is preferablymanufactured in a diameter of one and one-quarter to three inches, inone-eighth increments in size.

FIG. 4 is a schematic view illustrating exhaust gases, identified by thedirectional arrows therein, traveling through the various exhaust pipes12, through the venturi 16 and into the collector 14. The velocity ofthe exhaust gas increases from the exhaust pipes 12 into the venturi 16.The higher velocity exhaust gases are redirected by the vanes 18 suchthat the exhaust gases begin spinning within the venturi 16 and into thecollector 14. The vortex of spinning exhaust gases along the outer edgesof the venturi 16 and the collector 14 reduces the amount of turbulenceotherwise experienced in traditional automotive exhaust systems.Reducing the quantity of turbulence effectively increases the efficiencyof expelling the exhaust gases out through the collector 14. Efficientremoval of exhaust gases from within the exhaust system translates intoincreased performance of the IC engine. In the realm of automobiles, theoperator may experience more power, better fuel efficiency and betterresponse time of the engine. This is all due to the performance of theautomotive exhaust system 10 of the present invention through itsability to accelerate and efficiently move the exhaust gases through theventuri 16 and out through the collector 14. Of course, the size of theexhaust pipes 12, the collector 14, the venturi 16, and the size, shapeand curvature of the vanes 18 may vary depending on the application ofthe automotive exhaust system 10 of the present invention. For example,larger automobiles may require larger piping. Alternatively, the ratioof the diameter of the venturi 16 relative to the exhaust pipes 12 andthe collector 14 may also vary according to the desired application.Requirements may vary depending on the make and type of the vehicle withwhich the automotive exhaust system 10 would be fitted. The presentinvention disclosed herein has been directed to an automotive exhaustsystem. It is to be appreciated that the exhaust system is applicable toall forms of internal combustion exhaust systems and is not intended tobe limited to the precise application described herein.

Fluidity of the automotive exhaust system is an important aspect tomaximize performance of the internal combustion engine. Roughtransitions and unnecessary obstructions increase internal backpressureand rob efficiency. In an exemplary embodiment, the venturi 16 andcollector 14 are formed from a single tube of material throughspecialized tooling. Next, the vanes are welded inside and thereafterthe plurality of exhaust pipes are welded thereby forming the exhaustsystem described herein. This process results in a smooth form for theexhaust to flow through and results in increased performance. Referringto FIG. 1, the venturi 16 is defined having a converging section 20, areverse radius section 22 which is the actual venturi, a divergingsection 24, and a distal radius section 26. The converging section 20 istypically manufactured at 20 degrees relative to the axis of theincoming exhaust pipe 12. The reverse radius section 22 is typicallymanufactured from a reverse radius of 2 times the diameter of theexhaust pipes 12. The diverging section 24 is typically manufactured ata 7-10 degree angle relative to the axis of the exhaust pipe 12. Thedistal radius section 16 is typically manufactured at a radius 2 timesthe diameter of the exhaust pipe 12. Other variations of radii andangles may be used without departing from the scope of this invention.

Although several embodiments have been described in detail for purposesof illustration, various modifications may be made to each withoutdeparting from the scope and spirit of the invention. Accordingly, theinvention is not to be limited, except as by the appended claims.

1. An exhaust system, comprising: a plurality of exhaust pipes at aproximal end of the exhaust system for receiving internal combustionengine exhaust, the exhaust pipes having a combined cross-sectionalarea; a collector at a distal end of the exhaust system and having across-sectional area; a venturi disposed between and fluidly connectingthe exhaust pipes and collector, wherein a cross-sectional area thereofis less than either the collector cross-sectional area or the combinedexhaust pipes cross-sectional area; and a vane fixed to an inner wall ofthe venturi.
 2. The exhaust system of claim 1, wherein the vanecomprises an arced vane which matches the inner wall of the venturi. 3.The exhaust system of claim 1, wherein the vane is angled relative tothe adjacent inner wall of the venturi.
 4. The exhaust system of claim1, comprising a plurality of vanes fixed to the inner wall of theventuri.
 5. The exhaust system of claim 4, comprising at least one vanecorresponding to each exhaust pipe.
 6. The exhaust system of claim 5,wherein each vane is approximately centered relative to itscorresponding exhaust pipe.
 7. The exhaust system of claim 1, whereinthe collector and venturi are integrally formed from a single piece oftubing.
 8. An exhaust system, comprising: a plurality of exhaust pipesat a proximal end of the exhaust system for receiving internalcombustion engine exhaust, the exhaust pipes having a combinedcross-sectional area; a collector at a distal end of the exhaust systemand having a cross-sectional area; a venturi disposed between andfluidly connecting the exhaust pipes and collector, wherein across-sectional area thereof is less than either the collectorcross-sectional area or the combined exhaust pipes cross-sectional area;and at least one vane corresponding to each exhaust pipe fixed to aninner wall of the venturi.
 9. The exhaust system of claim 8, wherein thevane comprises an arced vane which matches the inner wall of theventuri.
 10. The exhaust system of claim 8, wherein the vane is angledrelative to the adjacent inner wall of the venturi.
 11. The exhaustsystem of claim 8, wherein each vane is approximately centered relativeto its corresponding exhaust pipe.
 12. The exhaust system of claim 8,wherein the collector and venturi are integrally formed from a singlepiece of tubing.
 13. An exhaust system, comprising: a plurality ofexhaust pipes at a proximal end of the exhaust system for receivinginternal combustion engine exhaust, the exhaust pipes having a combinedcross-sectional area; a collector at a distal end of the exhaust systemand having a cross-sectional area; a venturi disposed between andfluidly connecting the exhaust pipes and collector, wherein across-sectional area thereof is less than either the collectorcross-sectional area or the combined exhaust pipes cross-sectional area;and at least one vane corresponding to each exhaust pipe fixed to aninner wall of the venturi, wherein each vane is approximately centeredrelative to its corresponding exhaust pipe and comprises an arced vanewhich matches the inner wall of the venturi and is angled relative tothe adjacent inner wall of the venturi.